<template>
  <!-- 商品分类导航 -->
  <div class="type-nav">
    <div class="container">
      <div @mouseenter="mounseEnterTit" @mouseleave="mouseLeaveTit">
        <h2 class="all">全部商品分类</h2>
          <transition name="laoliu">
            <div class="sort" @mouseleave="crunt = -1" v-show="isShow">
              <div class="all-sort-list2">
                <!-- 一级 -->
                <div
                  class="item"
                  v-for="(cateGory , index) in cateGoryList"
                  :key="cateGory.categoryId"
                  :class="crunt === index? 'active' : '' "
                  @mouseenter="throttleEnter(index)"
                  @click="gotoSearch"
                >
                  <h3>
                    <a 
                      :data-cateGory1Id ="cateGory.categoryId"
                      :data-cateGoryName ="cateGory.categoryName"
                    >{{ cateGory.categoryName }}</a>
                  </h3>
                  <div class="item-list clearfix">
                    <div class="subitem">
                      <!-- 二级 -->
                      <dl
                        class="fore"
                        v-for="child in cateGory.categoryChild"
                        :key="child.categoryId"
                      >
                        <dt>
                          <a
                            :data-cateGory2Id ="cateGory.categoryId"
                            :data-cateGoryName ="cateGory.categoryName"
                          >{{ child.categoryName }}</a>
                        </dt>
                        <dd>
                          <!-- 三级 -->
                          <em
                            v-for="item in child.categoryChild"
                            :key="item.categoryId"
                          >
                            <a
                              :data-cateGory3Id ="cateGory.categoryId"
                              :data-cateGoryName ="cateGory.categoryName"
                            >{{ item.categoryName }}</a>
                          </em>
                        </dd>
                      </dl>
                    </div>
                  </div>
                </div>
              </div>
            </div>
          </transition>
      </div>
      <nav class="nav">
        <a href="###">服装城</a>
        <a href="###">美妆馆</a>
        <a href="###">尚品汇超市</a>
        <a href="###">全球购</a>
        <a href="###">闪购</a>
        <a href="###">团购</a>
        <a href="###">有趣</a>
        <a href="###">秒杀</a>
      </nav>
    </div>
  </div>
</template>

<script>
import _ from "lodash";
import { mapState } from "vuex";
export default {
  name: "NavType",
  data(){
    return{
      crunt: -1,
      isShow: false
    }
  },

  methods: {
    //1.编程式路由导航去search页面
    gotoSearch(e){
      if(e.target.nodeName === "A"){
        let query = {}

        const {category1id , category2id , category3id , categoryname} = e.target.dataset

        query.categoryName = categoryname

        if(category1id){
          query.category1Id = category1id
        }else if (category2id){
          query.category2Id = category2id
        }else if(category3id){
          query.category3Id = category3id
        }

        const params = this.$route.params
        this.$router.push({
          name: 'search',
          query,
          params,
        })
      }
    },

    //2.不是home组件不显示三级列表
    isNavShow(){
      if(this.$route.path === "/home"){
        this.isShow = true
      }
    },

    //3.移入显示
    mounseEnterTit(){
      if(this.$route.path === "/home") return
      this.isShow = true
    },

    //4.移出隐藏
    mouseLeaveTit(){
      if(this.$route.path === "/home") return
      this.isShow = false
    }

  },

  watch:{
    //监听路径改变隐藏三级列表
    $route:{
      handler(){
        this.isShow = false
      }
    }
  },

  mounted() {
    //1.使用lodash得到一个事件函数 移入的时候可以传参 核心函数能接受到参数
    this.throttleEnter = _.throttle(
      function center(index){
        this.crunt = index
      },
      30 , {leading: true , trailing: false}
    )

    //2.不是home组件不显示三级列表
    this.isNavShow()

  },
  computed: {
    //从vuex中拿到三级列表数据
    ...mapState("home", ["cateGoryList"]),
  },
};
</script>

<style lang="less" scoped>
//添加动画
.laoliu-enter,
.laoliu-leave-to{
  opacity: 0;
}

.laoliu-enter-active,
.laoliu-leave-active{
  transition: all 0.3s linear;
}

.type-nav {
  border-bottom: 2px solid #e1251b;

  .container {
    width: 1200px;
    margin: 0 auto;
    display: flex;
    position: relative;

    .all {
      width: 210px;
      height: 45px;
      background-color: #e1251b;
      line-height: 45px;
      text-align: center;
      color: #fff;
      font-size: 14px;
      font-weight: bold;
    }

    .nav {
      a {
        height: 45px;
        margin: 0 22px;
        line-height: 45px;
        font-size: 16px;
        color: #333;
      }
    }

    .sort {
      position: absolute;
      left: 0;
      top: 45px;
      width: 210px;
      height: 461px;
      position: absolute;
      background: #fafafa;
      z-index: 999;

      .all-sort-list2 {
        .item {
          h3 {
            line-height: 30px;
            font-size: 14px;
            font-weight: 400;
            overflow: hidden;
            padding: 0 20px;
            margin: 0;

            a {
              color: #333;
            }
          }

          .item-list {
            display: none;
            position: absolute;
            width: 734px;
            min-height: 460px;
            background: #f7f7f7;
            left: 210px;
            border: 1px solid #ddd;
            top: 0;
            z-index: 9999 !important;

            .subitem {
              float: left;
              width: 650px;
              padding: 0 4px 0 8px;

              dl {
                border-top: 1px solid #eee;
                padding: 6px 0;
                overflow: hidden;
                zoom: 1;

                &.fore {
                  border-top: 0;
                }

                dt {
                  float: left;
                  width: 54px;
                  line-height: 22px;
                  text-align: right;
                  padding: 3px 6px 0 0;
                  font-weight: 700;
                }

                dd {
                  float: left;
                  width: 415px;
                  padding: 3px 0 0;
                  overflow: hidden;

                  em {
                    float: left;
                    height: 14px;
                    line-height: 14px;
                    padding: 0 8px;
                    margin-top: 5px;
                    border-left: 1px solid #ccc;
                  }
                }
              }
            }
          }

          &.active {
            background-color: deepskyblue;
            .item-list {
              display: block;
            }
          }
        }
      }
    }
  }
}
</style>